Primary appendiceal adenocarcinomas are rare malignant neoplasms of the appendix. Carcinomas of the appendix are usually well-differentiated mucinous adenocarcinoma, which tend to produce pseudomyxoma peritonei, also known as gelatinous ascites, and do not show metastatic spread until late in the disease process. Umbilical metastasis from visceral malignancies described as Sister Mary Joseph nodule (SMJN) is rare and represents only 10% of all cutaneous metastases. To the best of our knowledge, only four cases of adenocarcinoma of the appendix metastasizing to the umbilicus have been reported in the medical literature. Here, we present a case of mucinous appendiceal adenocarcinoma which occurred in a 75-year-old female, who presented with SMJN.